Cervical lining, coloured scanning electron micrograph (SEM). The cervix is the canal that links the uterus (womb) to the vagina. It is lined with a moist mucous membrane that contains two types of cells, secretory cells and ciliated cells. The secretory cells (brown) secrete mucus in response to the female sex hormone oestrogen. They are covered in microscopic projections known as microvilli that increase the cell's surface area. The ciliated cells are covered in microscopic hair-like structures known as cilia (yellow). These beat in wave-like motions and function to move the sperm towards the uterus. Magnification: x80 when printed 10 centimetres wide.